おうぶくろむささびでしょう
大袋鼯鼠でしょう
ōbuku romusasabideshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of おおふくろももんが

1. Probably a giant flying squirrel.

Polite
Presumptive
Conjecture
Usually Written in Kana